78809387 has 4 divisors (see below), whose sum is σ = 79384776. Its totient is φ = 78234000.

The previous prime is 78809369. The next prime is 78809417. The reversal of 78809387 is 78390887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78390887 = 71 ⋅1104097.

It is a cyclic number.

It is not a de Polignac number, because 78809387 - 2⁶ = 78809323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78802387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287489 + ... + 287762.

It is an arithmetic number, because the mean of its divisors is an integer number (19846194).

Almost surely, 2^78809387 is an apocalyptic number.

78809387 is a deficient number, since it is larger than the sum of its proper divisors (575389).

78809387 is a wasteful number, since it uses less digits than its factorization.

78809387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575388.

The product of its (nonzero) digits is 677376, while the sum is 50.

The square root of 78809387 is about 8877.4651224322. The cubic root of 78809387 is about 428.7386635223.

The spelling of 78809387 in words is "seventy-eight million, eight hundred nine thousand, three hundred eighty-seven".